The invention relates to an adjustable spanner or screw wrench with a fixed jaw at the wrench head and a movable jaw, arranged on a slide glidably accommodated in the wrench head, said slide being adjustable in optional positions, by means of an adjusting screw or other means, and has a plate-like web running in a slot in the wrench head, there being a rod-shaped body in engagement with grooves in the side walls of the slide slot for retaining the slide in the slot.
In conventional screw wrenches, the rod-shaped body consists of a swelling on the slide web along its rack-toothed edge facing towards the adjusting screw. This conventional construction of the slide with an integral web and rod-shaped body, or slide rod, requires very great manufacturing accuracy to afford a good fit between the slide and its slot in the wrench head. In spite of tight tolerances, several different dimensions may interact unfavourably to spoil the fit.